The technique of envelope modulation is used to increase the efficiency of radio frequency power amplifiers. The supply voltage to the power amplifier is modulated according to the envelope signal of the radio frequency signal. In a split frequency envelope modulator, the envelope signal is split into two parts: a low frequency or DC component and a high frequency or AC component. These two components are amplified separately. The split frequency envelope modulator architecture increases the efficiency of envelope modulation; however, spilt frequency envelope modulators suffer from a phase transient at the cross-over frequency between the low frequency component and the high frequency component.